EPP

iTrader: (22)

Where's Smoky Yunick when you need him? lol Bob

TS6

iTrader: (41)

As far as the #7 cylinder problem, I have read (read: not SEEN) that the returnless fuel system on these F bodies causes alot of crap buildup in the fuel rail near that injector. Members here have posted this info, saying that they had to clean the junk out of the fuel rail. Undoubtedly this causes more debris buildup in the #7 injector, which obviously could cause a lean condition in that cylinder. Here's a good question: Has anyone ever lost #7 due to a leanout with aftermarket fuel rails and a return style fuel system? Without individual cylinder EGT monitoring its hard to say the carb style intake would be better for distribution on FI applications. I witnessed a Procharged C5 lose power on the dyno after the Vic jr. swap, but it also lost boost, which tells me it was flowing better. I don't know if it came back up after a pulley swap, I left.

HotRodKid

but why did he loose boost ? remember, intake pressure is a result of RESTRICION to flow. the real number that makes HP is actualy CFM ...if you install a less restictive intake (or heads, cam, exhaust. ect) you get more cfm at lower boost, resulting in more HP

if he lost boost due to the new intake having less restriction, then he should have gained power in the process because MORE air would have been getting into the system

now if they did the intake swap, and it wasnt sealing properly, he could have been loosing boost AND loosing hp, because air that was supposed to make it into the engine was just bleeding to atmosphere ... meaning less actual cfm made it into the engine

kp

iTrader: (34)

Yep, if you drop boost and the power drops you made the wrong change, if you dropped boost and the power stays the same you have accomplished a little something, if you drop boost and the power goes up then you really accomplished something.

I have swapped so many things on this car, dropped compression, cam, exhaust, got rid of the LS1 MAF and my boost level really hasnt changed more then 1psi but the car is running 2-3mph faster in the 1/8 mile and thats a big change..

stevieturbo

Also worth noting....

Logging 4th gear on the track from 5500rpm to 6900rpm.

My boost in July with the stock LS6/ stock ported TB and October with the carb intake.

Boost is identical, give or take 2-3kpa. ( ie virtually nothing )

LS2Camaro

iTrader: (5)

Thanks for your input on this stevieturbo. But to be more specific in which direction was that amount increase/decrease? Even if it was very small. Also what lbs of boost and how much rwhp are you making before/after?

LS2Camaro

iTrader: (5)

Also thanks to people in this post, especially KP,and stevieturbo I have decided to stick with Stock LS2 Intake as obviously there is no definitive gain going with the Carb style.

stevieturbo

The differences are extremely small. If I was to say which way, oddly I'd say it is making slightly more boost with the carb intake.
Its not enough though to say 100% one way or the other. I'm only comparing 1 run with each.


I'll give an example at 6000-6200rpm, 4th gear. Slight variations in rpm, due to logging data itself, but not so much it should matter, as the trends are the same.
July over the 2 runs I have logged. All mid-high 10's 143-145mph. Thought I had 3 runs logged, but can only find 2.

Stock LS6 intake with DIY ported stock TB.
6001.2rpm........220.8kpa
6200rpm...........229.2kpa

6022.0rpm......216.3kpa
6202.4rpm......225.3kpa

Carb intake in October, over 4 runs, as close to 6000-6200rpm as I can get.
5990.7rpm......229.5kpa
6241rpm........234.8kpa

6028rpm........227.7kpa
6240.2rpm.....232.9kpa

5098rpm........226kpa
6230.2..........232.4kpa

6027.7rpm......228kpa
6206.4rpm......231.6kpa


Now, I did make slight alterations to my belt drive before October, that might have provided better grip. But I dont believe the July runs suffered any slippage.
I have no idea what rwhp I am making, as I dont have access to a dyno to find out, so has never been dyno'd in its current configuration.

KHShapiro

iTrader: (10)

that does concern me a bit, just a little unless you are running a cog.
while i am at it are you running a cog? or the s-belt? If it is an s-belt what did you do to alter it? i am thinking you are running the s-belt just for the fact you are a stick and i would think the shock of a hard shift would snap a cog belt.

the increase in boost with about the same power seems odd to me.
That to me would mean the carb intake is then a restriction, am i wrong?

KHShapiro

iTrader: (10)

i reread and noticed you havent dyno'd before or after. so then the carb intake might be better after all, too bad you dont have a dyno to work with.

stevieturbo

Watch this video....obviously its not mine, but blower location etc is similar...Watch the belt.
I have boost pipes, very close to my belt, on the driven/long side. Watch how much the belt moves.
http://videos.streetfire.net/search/...1e0002aacc.htm

My setup is custom. YSi with a 12 rib, now using a Gates belt.
Previously, belts were shredding, I believe as the belt was allowed to build up vibrations, as there was a massive 19" or so without support on the driven side.
I added an idler there, reducing that to about 13". The idler is there just to stop any belt vibrations/wobble building up. It doesnt alter belt path to any degree.
The October weekend was circa 800 road miles, and 7 x 1/4 passes. I didnt have to do anything with the belt all weekend. I didnt re-tension it or anything, as everything stayed in check.

NOW...the runs in July were on a different branded 12 rib belt, and on the 4th pass it shredded shifting into 3rd. I dont believe I was having any noticable degree of slip though on the previous 3 runs.
The 2 logged runs were my first runs on that belt ( plus road miles ) and tension was checked immediately before the runs.


So assuming no slip on both setups, it would appear, the carb+85mm TB is posing more of a restriction, on my setup at least.

This would also be backed up, by the fact my tune changed very little. Its very hard for me to give a %% on fuelling, as shortly before I also swapped iinjectors from 660cc to 73lb. I did get a brief baseline tune with the new iinjectors, before switching the intake, and as already mentioned, fuelling requirements changed very little.
Due to how my ecu works, I do rely quite heavily on closed loop wideband to take control of fuelling, and quite often I do change my AFR targets.
But I was surprised, that overall inj pulse widths didnt change much.

Go figure....


of course it also brings the question...

If I am experiencing this....why hasnt anyone else ? Surely I cant be alone ?

its just a basic Victor nr, with typical elbow using a Accufab 85mm TB ( whats the point in going bigger, when IC pipework is 3" )

Got Me SOM

iTrader: (2)

I have read that you need to run a completely different cam when running this intake. there was a discussion about it in the internal engine section.

i'm sure in theory it "should" work better but other than looking cool under the hood i'm not convinced its superior than the stock ls6 manifold (assuming the car is making 1000 hp or less)

stevieturbo

I read most of that too..

But n/a can be so different to FI ( and indeed, Edelbrock offer different cams for carb applications )


Too many variables, and no apparent back to back testing has been done. So everything is guess work really.

obZidian

iTrader: (2)

ok.....

so what is it?

lol!! Currently im running a fast90mm and i wanted to ste up to a card/105mm tb. However, i wanted to see the difference between the two power and number wise. Ya'll think the fast will hold up to boost since it is a three piece unit?

stevieturbo

I think that one has been done too....

I dont recall having seen any threads, where a FAST has gained power over stock LS6 intake on a FI motor.

And again....if your IC pipework is 3" or 76mm ( I assume ).
Whats the point in a 105mm TB ?????

KHShapiro

iTrader: (10)

if i was a beting man (which i am) and maybe kp will back this up , you are having some sort of belt slippage. if it was a cog i would say no but even a 12 rib with what i am quessing is your power lvl ,but eitherway it still doesnt explain what is happening , at least in my eyes..... .

i would "think" if that where true you best turbo would be sized about 76mm with a proper ar. but it doenst work that way... i think..

could it be that your heads now cant keep up with the added air flow of the intake?

kp

iTrader: (34)

I thought you were going to stop dwelling on this lol.

KHShapiro

iTrader: (10)

yeah your right my bad

kp

iTrader: (34)

Besides the intake in your sig sure LOOKS good

IMO I dont think you made a bad decision on doing that intake, obviously you are doing a fairly high dollar build and since most of the faster cars out there are using them it makes perfect sense to use one. Like I said earlier on a F1 engine I dont think the intake is going to make or break the combination.

LS2Camaro

iTrader: (5)

But this is sooo much more fun, and Im learning alot. Thanks guys.